Lubricating device for sewing machine loop-takers



w. MYERS 2,101,320 CATING DEVICE FOR SEWING MACHINE LOOP TAKERS 'Dec. 7, 1937.

LUBRI Filed Dec.

W M m. D I D 3 8 1 m m f H L v u w ill/1911 Patented Dee. 7, 1937 2,101,320

UNITED STATES PATENT QFFICE LUBRICATING DEVICE FOR SEWING MA- CHINE LOOP-TAKERS Walter Myers, Bridgeport, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application December 28, 1936, Serial No. 117,712

3 Claims. (Cl. 112256) This invention relates to devices for supplying within this thread-case is a thread-bobbin l3 lubricant to thread-case raceways of sewing maconfined by a latch-member I4, said latch-memchine loop-takers, and more particularly loop her being pivotally supported by a bobbin-post takers of the vertical-axis rotary hook type, the i5 arising from the bottom wall ii of the thread- 5 invention having for its primary object to provide case. In its closed position, the latch member 5 means for so controlling the quantity of lubril4 overlies the upper flange of the bobbin i3 and cant supplied to the loop-taker raceway as to overhangs the rim of the thread-case wall H in insure that said raceway is sparingly but adethe usual manner. quately lubricated. The thread-case bearing-rib I0 is interrupted With the foregoing and other objects in view, to provide a thread-clearance gap between the 10 as will hereinafter appear, the present invention earing-rib ends which form opposed shoulders consists in the loop-taker raceway lubricating del6 and H. The bearing rib I0 is confined in the vice described in connection with the accompanyloop-taker raceway 9 by a gib I 8 secured by screws ing drawing, which illustrates a preferred eml9 upon the upper edge or rim of the loop-taker bodiment of the invention and in which: body, said gib l8 defining a segmental and re- Fig. 1 represents, in side elevation, a vertical movable portion of the loop-taker raceway. The axis rotary hook having an open-top thread-case, rim of the thread-case side wall also has a nose and illustrates fragments of the needle, throat- 0 e ing e e Stop-lugs 2| (only one Of plate and feed-dog of a sewing machine contain- Which is shown) at the under side of the throating the present improvement. Fig. 2 represents plate i, whereby the thread-case is restrained 20 a top plan view of the rotary hook shown in against rotation with the loop-taker. The usual Fig. 1, the thread-case journaled in the hook thread-tension spring 22 is secured by screws 23 being shown in horizontal section and the bobbin upon the side wall II of the thread-case, said being omitted. Fig. 3 represents a vertical sec- Sp functioning o impose a f c na ra v 25 tion of the hook and thread-case, the section upon the thread leading from the bobbin I3. 25

being taken substantially on the line 3-3 of Fig. 2 From the foregoing brief description, it will be and including the thread-bobbin. Fig. 4 reprenoted that the loop-taker and the thread-case sents in perspective and partly in section the represented are of conventional form as to derotary hook having an open-top thread-case. ta ls of Co struc io Fig. 5 represents asectional view similar to Fig. 3 The loop-taker 6 performs two rotations for 30 but showing the improvement as embodied in a each complete reciprocation of the needle 5 and, rotary hook having a capped thread-case. Fig. accordingly, at high speeds of operation of the 6 represents, in perspective and partly in section, machine it becomes necessary to lubricate the the rotary hook having the capped thread-case. bearing of the relatively stationary thread-case.

Referring more particularly to Figs. 1 to 4 While the qua y of lubricant pp to Said 35 inclusive of the drawing, the present improvement bearing m be adequate to obviate has been embodied in a sewing machine having duced overheating of the parts, an excess of lubrithe usual throat-plate I provided with a f dcant is objectionable because of attendant soiling slot 2, through which feed-slot operates a feedof the needle-thread loops successively cast about 40 dog 3 having a needle-aperture 4. The usual the thread-case by the loop-taker. Therefore, 40 vertically reciprocatory needle 5 cooperates with the difliculty presented is not, primarily, to pp y a loop-taker 6 disposed below the throat-plate, lubricant to the thread-case bearing but rather the loop-taker shown being of the vertical-axis to so control the lubricant that there is supplied rotary hook type. As illustrated, the loop-taker a minimum qua y adequate to meet q 6 has a cup-shaped body of which the cylindrical ments. 45 side wall is partly cut away to provide a thread- According to the present invention, a pad 24 loop seizing beak 1, said loop-taker being carried of suitable lubricant-absorbent material is held by a vertically disposed shaft 8 which may be against the outer face of the side-wall II of the rotated by any usual or suitable means. thread-case by a strap 25, secured at its opposite The inner face of the side wall of the loopends, by screws 26, to said side wall so as to 5 taker body is ciroumferentially recessed to provide lengthwise extend circumferentially of said wall an annular raceway 9. Journaled in the raceway directly above the level of the gib l8 and prefer- 9 s a bearing-rib I0 extending ir umferentially ably below the rim of the thread-case side wall. about the cylindrical side wall ll of an open-top Between its ends, the strap 25 is bent outwardly thread-case having a bottom wall t2. Disposed away from the side wall ll suificiently to re- 55 ceive the pad and, nevertheless, to be within the path of travel of the side wall of the loop-taker 6 at the base of the beak I. The lower edge of the pad is preferably held spaced slightly above the bearing rib i and also clear of the gib l8, thereby to obviate glazing of the pad by frictional contact, gib-clearance for the pad being provided in the present case by beveling the inner edge l8 of the gib l8.

Figs. and 6 of the drawing illustrate a capped thread-case provided with the present improvement, this type of thread-case having a shallow cup-shaped base-section 21 which is outwardly flanged at its rim to provide a bearing rib 28 journaled in the loop-taker raceway, said bearing rib having the usual loop-arresting shoulder 28. Rising centrally from said base section is a tubular post 29 for a thread-bobbin 30, the upper end of said post pivotally supporting a spring-pressed latch-member 3| serving to secure the cap-section 32 of the thread-case in bobbinenclosing position. The cylindrical side wall 32 of the cap-section has its rim fitting an annular recess 33 in the rim of the base-section 21, whereby the thread-bobbin is completely enclosed by the thread-case sections. The pad 24 and its securing strap 25 are disposed exteriorly of the capsection 32 in the same relationship of the parts as has been described in connection with the open-top thread-case.

It will be observed that the strap 25 has opposed side edges spaced from the cylindrical side wall of the thread-case, whereby the strap is open both at the top and at the bottom thereof so as to expose the upper and lower portions of the pad 24. Lubricant may therefore be conveniently supplied to the upper portion of the pad. Should the temperature of the side wall of the thread-case start to rise because of bearing friction, the viscosity of the lubricant is lessened and said lubricant thereupon gradually seeps down from the pad 24 along the outer face of the thread-case and upon the threadcase bearing rib 153, or 28. The seepage of the lubricant is slow because of the lubricant-holding nature of the pad 24, so that the lubricant is thereby controlled to sparingly lubricate the bearing rib. However, the quantity of lubricant thus supplied is adequate to meet requirements.

The pad 24 and its holding strap 25 are preferably so disposed circumferentially of the threadcase as to insure that the thread-loop cast about the thread-case cannot contact the pad. As illustrated in the drawing, the pad 24 is disposed beyond the bearing-rib shoulder l6 at the loopspreading side of the loop-taker and substantially medianly between the needle-thread loop-seizing position of the beak I and a point diametrically opposite thereto. As will be understood by those skilled in the art, the inner limb of the threadloop seized by the loop-taker beak 1 is engaged by the shoulder H5, or 28', and is thereby restrained against being carried into contact with the pad 24 or its holding strap 25. The upper portions of the pad 24 and its strap 25 are substantially at the level of the loop-taker rim at the base of the beak I, and consequently the outer limb of the thread-loop is also guarded against contacting said pad and strap.

Having thus set forth the nature of the invention, what I claim herein is:-

1. A rotary loop-taker for sewing machines, comprising a cup-shaped body provided with a thread-loop seizing beak and with an annular thread-case raceway, a thread-case having a cylindrical side wall provided with a circumferential bearing-rib journaled in said raceway, a pad-holding strap upon the outer face and lengthwise extending circumferentially of said cylindrical wall of the thread-case, said strap having opposed side edges spaced from said cylindrical wall, and a lubricant-absorbent pad secured against the outer face of said cylindrical wall by said strap.

2. A rotary loop-taker for sewing machines, comprising a body provided with a needle-threadloop seizing beak and with an annular raceway, a thread-case having a cylindrical side wall provided with a circumferential bearing-rib journaled in said raceway, a pad-holding strap detachably secured upon the outer face of said wall in spaced relation to said bearing-rib, said strap having opposed side edges spaced from said cylindrical wall, and a lubricant-absorbent pad interposed between said strap and said outer face of the thread-case wall.

3. A vertical-axis rotary loop-taker for sewing machines, comprising a body provided with a needle-thread-loop seizing beak and with an annular raceway, a segmental gib detachably secured upon said body and defining a portion of said raceway, a thread-case having a cylindrical side wall provided with a circumferential bearing-rib journaled in said raceway, a pad-holder disposed upon the outer face of said cylindrical wall entirely above the horizontal plane of said gib, and a lubricant-absorbent pad secured by said pad-holder against the outer face of said cylindrical wall above and in spaced relation to said bearing rib.

WALTER MYERS. 

